pollution: FILE typedef struct __FILE FILE; pollution: endgrent void endgrent(void); pollution: fgetgrent struct group* fgetgrent(FILE*); pollution: fgetgrent_r int fgetgrent_r(FILE* restrict, struct group* restrict, char* restrict, size_t, struct group** restrict); pollution: getgrent struct group* getgrent(void); pollution: getgrent_r int getgrent_r(struct group* restrict, char* restrict, size_t, struct group** restrict); pollution: opengr FILE* opengr(void); pollution: setgrent void setgrent(void);